1. Field of the Invention
The present invention generally relates to a pickup mechanism, and more particularly to a pickup mechanism capable of picking up papers steadily.
2. The Related Art
Referring to FIGS. 1-4, a pickup mechanism includes a main frame 50, a pickup module 60, and at least one stopper element 70. The main frame 50 has an upper cover 51 and an input tray 52. The pickup module 60 positioned in the upper cover 51 of the main frame 50 includes a pickup arm 61, a separation element 63 and a pickup element 64 of which both are restrained in the pickup arm 61. The pickup arm 61 defines a first blocking block 611 and a second blocking block 612. The stopper element 70 is set on the upper cover 51 of the main frame 50 and located between the separation element 63 and the pickup element 64. The stopper element 70 has a blocking portion 72 located at a bottom thereof and a resisting portion 74 located at a top thereof. The resisting portion 74 may movably resist against the first blocking block 611 for supporting the pickup module 60, and also may resist against the second blocking block 612 for limiting a rotating angle of the stopper element 70.
When papers are prepared to be put on the input tray 52, the pickup element 64 together with the pickup arm 61 of the pickup module 60 is raised up to a constant level and the resisting portion 74 of the stopper element 70 resists against the first blocking block 611 for supporting the pickup module 60 so as to make sure the papers are put on the input tray 52 successfully to reach the stopper element 70. When the papers are put on the input tray 52 by user, a pushing force of the papers needs conquer a friction between the resisting portion 74 and the first blocking block 611 to push away the blocking portion 72 for allowing the pickup element 64 to swing downward to pick up the papers. However, when a single piece of paper is put on the input tray 52, the single piece of paper has the poor pushing force to fail to push away the blocking portion 72 that makes the pickup element 64 have no way of picking up the single piece of paper. Furthermore, when a larger external force than the friction acts on the pickup mechanism, even if the external force just can conquer the friction between the resisting portion 74 and the first blocking block 611, the pickup element 64 of the pickup module 60 is apt to slip downward to affect putting the papers on the input tray 52. As a result, the pickup mechanism fails to pick up the papers steadily.